Is it possible that you're pressing the string too lightly, or too close to the fret? Either condition, or both together will tend to damp out the string's vibration, killing the sound. These errors can be compounded if you cradle the back of the neck in the web between your thumb and forefinger, because you tend to pull the strings down instead of pressing them onto the fretboard.

Try moving your fingertip to a point almost halfway back to the next lower fret, with your thumb on the back of the neck. Make sure you're pressing the string right down to the fretboard. Then pluck the string, and quickly roll your fingertip back and forth along the string, keeping the pressure on. You should find that ringing tone you seek.

Find the combination of location and pressure that sounds best to you. Then work on getting that combination at each finger of your chord formations, without the vibrato.

Don't get p_ssed... get better.